Use your own styles
You can add your own styles to affect the display
If you are comfortable with CSS and would like to add your own styles, simply write your CSS to your theme’s style.css file. If you are using a child theme, you would write it to the style.css file in that child theme’s folder. Child themes are used commonly in 3rd party, purchased, WordPress themes. Child theme style sheets allow you to override styles from plugins or the parent theme. See the codex here for a more in-depth review of child themes.